Auxiliary cutter for gold-dredgers.



lIn. n.. Posuslflwml-: I AUXILIARY GUTTER FUR GUILDl UREUGERS.

(Applimion'med Aug. 7, 1901.

(llo Modal.)

"lum/110% i III sa IN Umts PATENT FFICE.

ROBERT H. POSTLETHAITSE, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO' RISDON IRON AND LOCOMOTIVE WORKS, OF SAN FRANCISCO, CALI- FORNIA, A CORPORATION OF CALIFORNIA.

AUXILIARY CUTTER FOR GOLD-DREDGERS.

SEEGIFIGATION forming :part of Letters Patent No. 696,078, dated March 25, 1902. Application filed August 7, 1901. Serial No. 71,195. (No model.)

To @ZZ whom t may concern: ings of the ladder. Overthe tumbler A Be it known that I, ROBERT H. POSTLE- works the endless carrier B', to which is at- THWAITE, a citizen of Great Britain, residing tached the cutting-buckets C. These buckets in the city and countyof San Francisco, State not only act as cutters for the material to be 5 of California, have invented certain new and worked, but elevare and deposit the same 55 useful Improvementsin Auxiliary Cutters for to suitable means for' treating the material. Gold-Dredgers; and I do hereby declare the The buckets C cut only in a direct line with following to be a full, clear, and exact dethe working face thereof. Hence whenever scription of the same. the boat, oat, or platform is swung to one side Io The invention relates to that class or type to change the cut of the buckets considerable 6o of gold-dredging apparatus provided with a strain is placed upon the swinging ladder. swinging ladderover which works an endless This is due to the fact ihatsufiicient poweris or chain-bucket excavator; and the object of required to force the sides of the ladder into the invention is to provide means to aid the the embankment to be worked in order togive i5 main cutters or cutting-buckets to remove a clearance for the cutting-bucket. The lateral C5 portion of the side wall of theembankment strain to which the ladder is subjected durduriug the lateral movement of the ladder, ing the side movement of the dredge not only thus creating a clearance for` the ladder and weakens the swinging ladder, but delays the permitits side movement to place the cuttingwork of entering new ground during the 2o buckets in line with the face of the embankworking of the dredger. The tumbler-shaft 7o ment or material to be removed. Ordinarily B is extended a short distance beyond the it is required during the side or lateral movesides of the ladder, and said shaft has sement of the ladder that suftlcient pressure be cured thereto the disks D D. Each disk has exerted to force the side thereof into the ema series of pockets as formed in its periphery,

25 bankment a sufficient depth to place the cutand in these pockets are riveted or otherwise 75 ting edge of the bucket in line with the face rigidly secured the teeth l 2 3, each toothbethereof. This subjects the ladder to a severe ing provided with a removable steel cuttingstrain and ofttimes weakens the same. It is point 4. By thus making the cutting-points this excessive strain tothe ladder which the separate from the 1 teeth new ones may be 3o presentinvention is mainly designed to obvireadily supplied in case of one becoming 8o ate and by so doing increase the efticiencyof broken or damaged and necessity of throwthe dredger. ing-away the entire tooth obviated. Each To comprehend the invention,.refe`rence cutting-tooth is arranged at an outward inshouldbe had to the'accompanying drawings, clination, so as to permit of the teeth pene- .35 whereintrating the soil of the side embankment some- 85 Figure l is a side View disclosing the lower what in advance of the ends of the tumblerportion of the swinging ladder, the tumbler Ishaft carrying the main cutters. The cutters working therein, bucketcarrier working are driven in the present case by the movethereover, and the auxiliary cutters secured ment of the tumbler, which has a step rota- `4o to the tumbler-shaft beyond the sides of the tion imparted thereto by the travel of the-9o swinging ladder; and Fig. 2 is a plan View of endless carrier thereover. the mechanism disclosed by Fig. 1 of the draw- It will be understood that the auxiliary cutings, the endless carrier being removed. ters are not designed to act with the cutting- In the drawings the letter A is used to inbuckets in their work ofcutting and remov- 45 dicate the swinging ladder, which usually ing the cut material, but simply as an aid 95 works within a well in the dredge boat, iioat, thereto in preparing the way for the cuttingor platform. (Not shown.) At the bottom buckets entering a new cut with the least or lower end of said ladder Works, between resistance as to side advance or swing of the the side pieces thereof, the tumbler A', which vertically-movable swinging ladder. A clear- 50 is mounted upon the shaft B, workingin bearance is thus made for the lateral movement Ioo or swing of the ladder, and the Work of removing the excavated material thus expedited to such extent.

Having thus described the invention, what is claimed as new, and desired to be protected by Letters Patent, is

l. In combination substantially as described, a rotary tumbler, a shaft therefor, a disk secured to the outer end of said shaft and provided with pockets around its periphery, and laterallyburved cutting-teeth riveted in said pockets, substantially as described.

2. In combination substantially as described, a rotary shaft, oppositely-disposed disks secured thereto and provided with pockets in their peripheries, and cutting-teeth rigidly secured, one in each pocket, substantially as described.

3. In combination substantially as described, a rotary tumbler, a shaft therefor, disks D secured to the outer ends ofthe shaft, laterally-curved cutting-teeth secured to each disk, and removable cutting-points 4 at the outer ends of said curved teeth, substantially as described.

In Witness whereof I have hereunto set my hand.

ROBERT H. POSTLETHWAITE.

Witnesses:

N. A. ACKER, WALTER F. VANE. 

